How is the margin between plots manipulated?

Question

I have three groups, each containing a pair of barplots. I would like to add space between each group, so there is some distinction. However, when I manipulate the margins via mar parameter in par(), it affects the width of the barplot.

par(mfrow=c(1,6))
#pair1 
par(mar=c(5,2,5,1), xpd=TRUE)
barplot(t(cbind(1, 5, 6)), col=c("red", "orange", "yellow"))
par(mar=c(5,2,5,2), xpd=TRUE)
barplot(t(cbind(3, 3, 2)), col=c("blue", "green", "purple"))

#pair2
par(mar=c(5,4,5,1), xpd=TRUE)
barplot(t(cbind(2, 2.5, 5)), col=c("red", "orange", "yellow"))
par(mar=c(5,2,5,2), xpd=TRUE)
barplot(t(cbind(5, 1, 3)), col=c("blue", "green", "purple"))

#pair2
par(mar=c(5,4,5,1), xpd=TRUE)
barplot(t(cbind(4, 2, 1)), col=c("red", "orange", "yellow"))
par(mar=c(5,2,5,2), xpd=TRUE)
barplot(t(cbind(6, 2, 1)), col=c("blue", "green", "purple"))

How can I add more space in between the 3 plots while maintaining the width of the barplots? Appreciate any advice.

Greg Snow Greg Snow · Accepted Answer · 2015-03-18T19:46:23

I would suggest using the layout function instead of par(mfrow=c(1,6)) and specify the space between the 3 pairs as additional "blank" plotting regions.

Here is a simple example:

tmpmat <- rbind(c(1,2,0,3,4,0,5,6))
layout(tmpmat, widths=c(3,3,1,3,3,1,3,3))

barplot(rbind(1,5,6))
barplot(rbind(3,3,2))

barplot(rbind(2,2.5,5))
barplot(rbind(5,1,3))

barplot(rbind(4,2,1))
barplot(rbind(6,2,1))

Another possibility is to combine all your vectors into a matrix and create 1 barplot and then use the space argument to control the spaces between the stacked bars (I believe that this is what @PedroBraz's answer was meant to convey. This will put all the bars on the same vertical scale while your and my example gives each barplot its own vertical scale.

How is the margin between plots manipulated?

2 Answers